U.S. cyclist Floyd Landis poses for a picture during a visit to his former Phonak team before the last stage of the Tour of Spain cycling race in central Madrid September 17, 2006. It has been a challenging year for Floyd Landis, whose Tour de France victory made the retirement of seven-times winner Lance Armstrong less painful for Americans. Just days after claiming victory on the Champs-Elysees in Paris, however, Landis was found to have tested positive for testosterone. Picture taken September 17, 2006. To match feature YEARENDER-NORTHAMERICA REUTERS/Victor Fraile (SPAIN)

Phonak's team rider Floyd Landis of the U.S., wearing the leader's yellow jersey, holds a U.S. flag as he takes his lap of honor around the Champs Elysees after winning the 93rd Tour de France cycling race after the final stage between Sceaux-Antony and the Champs-Elysees in Paris, July 23, 2006. It has been a challenging year for Floyd Landis, whose Tour de France victory made the retirement of seven-times winner Lance Armstrong less painful for Americans. Just days after claiming victory on the Champs-Elysees in Paris, however, Landis was found to have tested positive for testosterone. Picture taken July 23, 2006. To match feature YEARENDER-NORTHAMERICA REUTERS/Stefano Rellandini (FRANCE)

Golfer Tiger Woods of the U.S. hits his tee shot at the 17th hole during his win at the PGA Grand Slam of Golf in Poipu, Hawaii, November 22, 2006. For the eighth time in 10 years, Tiger Woods was the golfer of the year. Woods won 10 titles overall, including the British Open, and nearly $10 million in 2006 -- all the more remarkable considering he took nine weeks off to cope with the illness and subsequent death of his father Earl. Picture taken November 22, 2006. To match feature YEARENDER-NORTHAMERICA REUTERS/Robert Galbraith (UNITED STATES)

Tiger Woods of the U.S. acknowledges the gallery after finishing the 9th hole during the first round of the Dunlop Phoenix golf tournament at the Phoenix Country Club in Miyazaki, Japan, November 16, 2006. For the eighth time in 10 years, Tiger Woods was the golfer of the year. Woods won 10 titles overall, including the British Open, and nearly $10 million in 2006 -- all the more remarkable considering he took nine weeks off to cope with the illness and subsequent death of his father Earl. Picture taken November 16, 2006. To match feature YEARENDER-NORTHAMERICA REUTERS/Toru Hanai (JAPAN)

A demonstrator wearing a mask depicting U.S. President George W. Bush takes part in a protest as Bush participates in a summit of North American leaders with counterparts Vicente Fox, President of Mexico, and Stephen Harper, Prime Minister of Canada, in Cancun March 30, 2006. REUTERS/Victor Ruiz

Mexican President Vicente Fox (C) and Canadian Prime Minister Stephen Harper shake hands, next to U.S. President George Bush (L), after their joint news conference at the conclusion of their two-day summit in Cancun, March 31, 2006. REUTERS/Andrew Winning

Mexican President Vicente Fox (C) speaks as U.S. President George Bush (L) and Canadian Prime Minister Stephen Harper look on during their joint news conference at the conclusion of their two-day summit in Cancun March 31, 2006. REUTERS/Andrew Winning

A demonstrator protests against U.S. President George W. Bush as he participates in a summit of North American leaders with counterparts Vicente Fox, President of Mexico, and Stephen Harper, Prime Minister of Canada, in Cancun March 30, 2006. The banner reads "Bush Murderer" in Spanish. REUTERS/Victor Ruiz

Mexican President Vicente Fox (L), U.S. President George Bush (C) and Canadian Prime Minister Stephen Harper stand on the Castle, or Kukulkan Pyramid, at the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Demonstrators hold up a banner during a protest outside the Mayan ruins of Chichen Itza after Canadian Prime Minister Stephen Harper, Mexican President Vicente Fox and U.S. President Bush toured the archaeological site in Mexico's Yucatan peninsula March 30, 2006. The three north American leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. The banner reads "Bush, Genocidal Killer". REUTERS/Andrew Winning

U.S. President George Bush (L), Mexican President Vicente Fox (2nd L) and Canadian Prime Minister Stephen Harper watch traditional dancers perform during a tour of the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The North American leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

U.S. President George Bush (2nd L), Mexican President Vicente Fox (3rd L) and Canadian Prime Minister Stephen Harper (4th L) watch traditional dancers perform during a tour of the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula with archaeologist Federica Sodi March 30, 2006. The leaders of North America began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

Mexican President Vicente Fox (C), U.S. President George Bush (L) and Canadian Prime Minister Stephen Harper stand in front of the Castle, or Kukulkan Pyramid, at the Mayan ruins of Chichen Itza in Mexico's Yucatan Peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

A mock wanted poster featuring U.S. President George Bush is seen pasted to railings in front of riot police during a protest outside the Mayan ruins of Chichen Itza just after Canadian Prime Minister Stephen Harper, Mexican President Vicente Fox and Bush toured the archaeological site in Mexico's Yucatan peninsula March 30, 2006. The three north American leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

Demonstrators hold up a banner protesting against U.S. President Bush in front of riot police outside the Mayan ruins of Chichen Itza just after Canadian Prime Minister Stephen Harper, Mexican President Vicente Fox and Bush toured the archaeological site in Mexico's Yucatan peninsula March 30, 2006. The three north American leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

Mexican President Vicente Fox (R), U.S. President George Bush (2nd R) and Canadian Prime Minister Stephen Harper (2nd L) tour the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula with archaeologist Federica Sodi March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

U.S. President George Bush (L) requests a dancer's hat after it blew off as Mexican President Vicente Fox (C) and Canadian Prime Minister Stephen Harper watch traditional dancers during a tour of the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

Mexican President Vicente Fox (C) looks on as U.S. President George Bush (R) and Canadian Prime Minister Stephen Harper shake hands after a tour of the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

Mexican President Vicente Fox (C) and U.S. President George Bush (R) shake hands as Canadian Prime Minister Stephen Harper looks on after a tour of the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

Canadian Prime Minister Stephen Harper (L), U.S. President George Bush (C) and Mexican President Vicente Fox tour the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

U.S. President George Bush (L) receives a dancer's hat after it blew off as Mexican President Vicente Fox (C) and Canadian Prime Minister Stephen Harper watch traditional dancers during a tour of the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Andrew Winning

Canadian Prime Minister Stephen Harper (R) and Mexican President Vicente Fox watch traditional dancers perform during a tour of the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. Harper, Fox and U.S. President George Bush began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

U.S. President George Bush (L), Mexican President Vicente Fox (C) and Canadian Prime Minister Stephen Harper tour the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Canadian Prime Minister Stephen Harper (R) and U.S. President George Bush watch traditional dancers perform during a tour of the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. Harper, Bush and Mexican President Vicente Fox began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Canadian Prime Minister Stephen Harper watches traditional dancers perform during a tour of the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. Harper and his two North American counterparts, U.S. President George Bush and Mexican President Vicente Fox, began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Canadian Prime Minister Stephen Harper (L), Mexican President Vicente Fox (2nd L) and U.S. President George Bush (R) are guided through the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula by archaeologist Federica Sodi March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Mexican President Vicente Fox (L), U.S. President George Bush (C) and Canadian Prime Minister Stephen Harper pose on the Castle, or Kukulkan Pyramid, as they tour the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

U.S. President George Bush (L), Canadian Prime Minister Stephen Harper (C) and Mexican President Vicente Fox tour the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Mexican President Vicente Fox (L), U.S. President George Bush (C) and Canadian Prime Minister Stephen Harper climb the Castle, or Kukulkan Pyramid, as they tour the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Mexican President Vicente Fox (L), U.S. President George W. Bush (R) and Canadian Prime Minister Stephen Harper greet each other as they arrive to tour the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Mexican President Vicente Fox (C), U.S. President George Bush (R) and Canadian Prime Minister Stephen Harper talk as they arrive to tour the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Mexican President Vicente Fox (L), U.S. President George Bush (R) and Canadian Prime Minister Stephen Harper greet each other as they arrive to tour the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Mexican President Vicente Fox (C), U.S. President George Bush (R) and Canadian Prime Minister Stephen Harper stand in front of the Castle, or Kukulkan Pyramid, at the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. The three leaders began their meetings in Cancun to discuss immigration, border security and trade with a visit to the Chichen Itza ruins. REUTERS/Chris Wattie

Mexican President Vicente Fox (L), U.S. President George Bush (C) and Canadian Prime Minister Stephen Harper stand on the Castle, or Kukulkan Pyramid, at the Mayan ruins of Chichen Itza in Mexico's Yucatan peninsula March 30, 2006. Bush, Fox and Harper are in Cancun to discuss security and immigration issues. REUTERS/Andrew Winning